Things started off benign enough. Through the first three possessions on Sunday, the Rams' offense had failed twice, Washington's once.
It was, perhaps expectedly, marked by the sloppiness on offense through those first six minutes plus.
Then, this happened.
Washington RB Alfred Morris curled from the running up the gut to the sideline through an arm tackle attempt by Rams S Rodney McLeod for 35 yards and changed the entire game.
With their three-TE look, especially in power formations, Washington could sell the run hard. And when the Rams overpursued, as they did often, it left a ton of space at the second level.
Look at how the Morris run developed.
You see the assignments here. Every defender has a blocker assigned. In order to stop this one, one of the Rams is going to have to shed his blocker and fill the gap. DT Aaron Donald is nearly in on the handoff which will push Morris into the gut of the defensive line...except nobody's there. Will Hayes and Alec Ogletree are well blocked out on the strong side with four Rams on weakside all accounted for. And the pre-handoff motion is dragging them toward that weakside. You can se James Laurinaitis vacating the middle of the field toward the stretch play on the outside.
Except that's not where Morris is going.
Morris has taken the ball up the middle between Laurinaitis and DE William Hayes, both being properly blocked. The secondary is nowhere close, with S T.J. McDonald and CB Trumaine Johnson down on the strong side of the field. McLeod is out of view, but he's coming...
...but just as he shows up, Morris cuts it outside. Because nearly the entire Rams defense is behind him, Morris doesn't have to worry about anything except to protect the ball as he allows WR Andre Roberts to set up his block on CB Janoris Jenkins.
Hayes eventually catches up to him, but it's too late. The face of the game has changed. Now, the Rams have to begin playing catch-up because they're struggling to win 1v1 battles on run defense. Once that came apart, everything else did as well.
Morris would only rush for 24 yards on his 17 other carries, but rookie and fellow Washington RB Matt Jones would cleave the Rams' defense for 123 yards on just 19 carries.
Morris run unlocked it, and the Rams never found a way to shut the door.